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What’s In Your Drinking Water?

November 5, 2012

Water quality is a concern to all of us today, no matter where we live. Fortunately, people who get their drinking water from a municipal source are able to access free information about local water quality conditions simply by contacting their local water utility. The U.S. Environmental Protection Agency (EPA) requires all water utilities to provide their customers with a Consumer Confidence Report (CCR), which can be used to help you make decisions about the type of drinking water your family consumes.

Since 1999, these federally mandated reports have been distributed to help raise consumer awareness about drinking water quality and to educate the public about local drinking water issues. Although the format can vary slightly by community, each report provides information about the community's drinking water source, the treatment processes, and any contaminants detected in the community's tap water.

What’s in the Report?

Most reports begin with an overview of the community's drinking water system. Following the overview is an explanation of the abbreviations used in the report. The most important ones to understand are MCL, or maximum contaminant level, which is the maximum level at which a contaminant can be present in the water according to EPA or state standards. Also important is the unit of measurement used in the local community. Some communities use milligrams per liter (mg/L) or parts per million (ppm), while others may use micrograms per liter (ug/L) or parts per billion (ppb). When comparing detected contaminant levels against federal standards, make sure that the units of measurement in your utility's report are consistent with those used in the EPA standards. (Note: 1 ppm equals 1,000 ppb.)

Next are the contaminant tables, which list the contaminants detected in the community's tap water supply. When reading these tables, begin at the left with the contaminant name. To the right of the contaminant name is the unit of measurement. The next column usually indicates either the MCL or the amount of the contaminant detected in the community's tap water supply. Most communities include both an average as well as a range detected for each contaminant. On the far right is the potential source of that contaminant, followed by whether there were any violations during the year, meaning that a contaminant was detected over the permitted maximum level.

Using This Information

To interpret this information, simply take the amount of the contaminant that was detected in the water supply and compare it to the MCL (although you may see some contaminants for which no MCL has been established). Most community water supplies have very good water quality and few contain contaminants at a level that exceeds the MCL. However, some people, such as individuals with compromised immune systems, may be more vulnerable than the general population to the presence of some contaminants. Understanding these concerns is one of the important reasons to get these reports and read them thoroughly every year.

Home Water Treatment

For many reasons, more people are opting to use a home water treatment device. Because there are so many different types of water treatment products on the market, it can be difficult to decide which one to purchase.

To ensure you are getting a device that will meet your specific needs, first try to identify your specific water quality concerns. Does the water have a funny taste, odor or color, or did the community’s water quality report indicate the water contained a high level of a particular contaminant? Because no one product can reduce all contaminants, it’s important to take the time to identify which contaminants are of local concern, and make sure the water treatment system you choose to purchase is certified to address them effectively.

A variety of products and technologies can be used to treat drinking water. Some products use an adsorbent filter made of carbon or charcoal, while others may use a membrane or a resin to reduce contaminants. Home water treatment devices also come in a wide range of styles, from pour-through water pitchers, to faucet-mount filters, to plumbed-in systems that can treat either the water coming from a single faucet or all water used throughout the home.

When shopping for products, you may see references to American National Standards like NSF/ANSI 42, 44, 53, 55, 58, 62 or 401. Each of these standards either applies to a specific product type or contains a special set of contaminant reduction testing protocols. For example, NSF/ANSI 42 and NSF/ANSI 53 cover systems that use filtration technology, while NSF/ANSI 44 applies to salt-based softeners. NSF/ANSI 55 contains design and performance requirements for ultraviolet disinfection systems, while NSF/ANSI 58 and NSF/ANSI 62 contain similar requirements for systems that use reverse osmosis or distillation respectively. NSF/ANSI 401 is the newest NSF standard, designed to evaluate the ability of water treatment devices to effectively reduce several different types of emerging contaminants in drinking water, including some pharmaceuticals, over-the-counter medications, herbicides, pesticides and chemicals used in manufacturing like bisphenol A (BPA).

Because residential water treatment products are not federally regulated, it’s important to verify that the system is tested and certified against one of the above standards to meet your specific contaminant reduction needs before purchasing. In some situations, it may not be possible to locate a water treatment product that is certified to treat a particular contaminant, so another option is purchasing certified bottled water to meet cooking and drinking water needs. Lastly, keep in mind that most residential water treatment systems require some type of regular maintenance or replacement of the entire unit after a certain number of gallons. Protect your family by making sure that the system you purchase is independently certified, and always follow the manufacturer’s installation and maintenance instructions carefully.